Moisture separators are of particular use in the electricity generating and process industries. For example, steam turbine power plants frequently comprise moisture separators in order to minimize the amount of water droplets in the pressurized steam driving the steam turbine and thereby minimize the risk of damage to turbine blading and other components due to erosion and corrosion. A moisture separator is arranged in a power plant so to subject the steam flow to moisture separation prior to its entry to the turbines.
A type of moisture separator known from U.S. Pat. No. 4,342,570 comprises stacked bundles of parallel and spaced-apart corrugated wafers or chevron-type plates housed in panels that are bolted to a support structure. A perforated sheet bolted to the support structure and placed upstream from the panels distributes the incident flow of wet steam in a uniform manner. The corrugated wafers are positioned so that the corrugations run at right angles to the direction of flow of the steam. This imparts a wave-like motion to the steam as it flows between the parallel and spaced-apart wafers and past the corrugations, so that the water droplets, having more inertia than the surrounding steam, are intercepted by the corrugations instead of remaining entrained in the steam. The corrugated wafers are tilted down at an angle relative to the horizontal, so that the trapped droplets run down the troughs of the corrugations to gutters that are placed to capture the water as it leaves the corrugated plates. The water is removed from the moisture separator through drain tubes connected to the ends of the gutters.
EP462687 discloses a moisture separator having a stack of spaced-apart vanes comprising members arranged to form a zigzag-shaped contour. A flow of gas or vapor flows through the spaces between the vanes encountering the zigzag shape of the vanes. Each member of the vanes has upstream and downstream cavities, in which water droplets are collected and can run down, and the water can be collected at the bottom end of the vane. The cavities on the members require that the space between the vanes be of a given minimum dimension.
EP 1755763 discloses a further moisture separator device having spaced-apart parallel profiled plates, between which passes a vapor flow. The device comprises one or more ribs extending at right angles to the vapor flow direction and designed to generate a flow resistance. The profiled plates are essentially corrugated plates, which comprise on each maximum of its profile a protrusion or pocket directed opposite the vapor flow direction and designed to catch the moisture and direct it to a collection volume.